add file locking

go.mod

@@ -2,4 +2,12 @@ module github.com/objectbox/objectbox-generator
 
 go 1.11
 
-require github.com/google/flatbuffers v23.5.26+incompatible
+require (
+	github.com/gofrs/flock v0.8.1
+	github.com/google/flatbuffers v23.5.26+incompatible
+)
+
+require (
+	golang.org/x/sys v0.24.0 // indirect
+	gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c // indirect
+)

go.sum

@@ -1,2 +1,13 @@
+github.com/gofrs/flock v0.8.1 h1:+gYjHKf32LDeiEEFhQaotPbLuUXjY5ZqxKgXy7n59aw=
+github.com/gofrs/flock v0.8.1/go.mod h1:F1TvTiK9OcQqauNUHlbJvyl9Qa1QvF/gOUDKA14jxHU=
 github.com/google/flatbuffers v23.5.26+incompatible h1:M9dgRyhJemaM4Sw8+66GHBu8ioaQmyPLg1b8VwK5WJg=
 github.com/google/flatbuffers v23.5.26+incompatible/go.mod h1:1AeVuKshWv4vARoZatz6mlQ0JxURH0Kv5+zNeJKJCa8=
+github.com/kr/pretty v0.2.1 h1:Fmg33tUaq4/8ym9TJN1x7sLJnHVwhP33CNkpYV/7rwI=
+github.com/kr/pretty v0.2.1/go.mod h1:ipq/a2n7PKx3OHsz4KJII5eveXtPO4qwEXGdVfWzfnI=
+github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
+github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
+github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
+golang.org/x/sys v0.24.0 h1:Twjiwq9dn6R1fQcyiK+wQyHWfaz/BJB+YIpzU/Cv3Xg=
+golang.org/x/sys v0.24.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=

internal/generator/generator.go

@@ -31,6 +31,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/gofrs/flock"
 	"github.com/objectbox/objectbox-generator/internal/generator/model"
 )
 
@@ -74,18 +75,17 @@ type CodeGenerator interface {
 }
 
 // WriteFile writes data to targetFile, while using permissions either from the targetFile or permSource
-func WriteFile(file string, data []byte, permSource string) error {
+func WriteFile(targetFile string, data []byte, permSource string) error {
 	var perm os.FileMode
 	// copy permissions either from the existing file or from the source file
-	if info, _ := os.Stat(file); info != nil {
+	if info, _ := os.Stat(targetFile); info != nil {
 		perm = info.Mode()
 	} else if info, err := os.Stat(permSource); info != nil {
 		perm = info.Mode()
 	} else {
 		return err
 	}
-
-	return ioutil.WriteFile(file, data, perm)
+	return ioutil.WriteFile(targetFile, data, perm)
 }
 
 // Process is the main API method of the package
@@ -134,31 +134,57 @@ func Process(options Options) error {
 
 	var modelInfo *model.ModelInfo
 
-	modelInfo, err = model.LoadOrCreateModel(options.ModelInfoFile)
-	if err != nil {
-		return fmt.Errorf("can't init ModelInfo: %s", err)
-	}
+	var lockPath = options.ModelInfoFile + ".lock"
+	fileLock := flock.New(lockPath)
 
-	modelInfo.Rand = options.Rand
-	defer modelInfo.Close()
+	var retries = 5
+	var locked bool = false
 
-	if err = modelInfo.Validate(); err != nil {
-		return fmt.Errorf("invalid ModelInfo loaded: %s", err)
+	for !locked && retries > 0 {
+		locked, err = fileLock.TryLock()
+		if !locked || err != nil {
+			fmt.Println("LOCKED.. SLEEPING")
+			time.Sleep(1 * time.Second)
+			retries--
+		}
 	}
 
-	// if the model is valid, upgrade it to the latest version
-	modelInfo.MinimumParserVersion = model.ModelVersion
-	modelInfo.ModelVersion = model.ModelVersion
+	if locked {
+		defer func() {
+			if err := fileLock.Unlock(); err != nil {
+				panic(err)
+			}
+		}()
 
-	if err = createBinding(options, modelInfo); err != nil {
-		return err
-	}
+		modelInfo, err = model.LoadOrCreateModel(options.ModelInfoFile)
+		if err != nil {
+			return fmt.Errorf("can't init ModelInfo: %s", err)
+		}
+
+		modelInfo.Rand = options.Rand
+		defer modelInfo.Close()
+
+		if err = modelInfo.Validate(); err != nil {
+			return fmt.Errorf("invalid ModelInfo loaded: %s", err)
+		}
 
-	if err = createModel(options, modelInfo); err != nil {
+		// if the model is valid, upgrade it to the latest version
+		modelInfo.MinimumParserVersion = model.ModelVersion
+		modelInfo.ModelVersion = model.ModelVersion
+
+		if err = createBinding(options, modelInfo); err != nil {
+			return err
+		}
+
+		if err = createModel(options, modelInfo); err != nil {
+			return err
+		}
+
+		return nil
+
+	} else {
 		return err
 	}
-
-	return nil
 }
 
 func createBinding(options Options, storedModel *model.ModelInfo) error {

internal/generator/model/fileio.go

@@ -30,15 +30,62 @@ import (
 
 // LoadOrCreateModel reads a model file or creates a new one if it doesn't exist
 func LoadOrCreateModel(path string) (model *ModelInfo, err error) {
+
+	/*
+		var lockPath = path + ".lock"
+		fileLock := flock.New(lockPath)
+
+			lockCtx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
+			defer cancel()
+			locked, err := fileLock.TryLockContext(lockCtx, 100*time.Millisecond)
+			if err != nil {
+				fmt.Println("LOCK FAILED")
+				return nil, err
+			}
+			if locked == false {
+				fmt.Println("LOCK FAILED")
+			}
+	*/
+
+	/*
+		var retries = 5
+		var locked bool = false
+
+		for !locked && retries > 0 {
+			locked, err = fileLock.TryLock()
+			if !locked || err != nil {
+				fmt.Println("LOCKED.. SLEEPING")
+				time.Sleep(1 * time.Second)
+				retries--
+			}
+		}
+
+		if locked {
+			defer func() {
+				if err := fileLock.Unlock(); err != nil {
+					panic(err)
+				}
+			}()
+	*/
 	if fileExists(path) {
 		return LoadModelFromJSONFile(path)
 	}
 	return createModelJSONFile(path)
+	/*
+		} else {
+			return nil, err
+		}a
+	*/
 }
 
 // Close and unlock model
 func (model *ModelInfo) Close() error {
 	return model.file.Close()
+	/*
+	   var err = model.file.Close()
+	   model.file.Sync()
+	   return err
+	*/
 }
 
 // Write current model data to file

test/cmake/cmake.go

@@ -195,7 +195,7 @@ func (cmake *Cmake) BuildTarget() ([]byte, []byte, error) {
 func (cmake *Cmake) BuildDefaults() ([]byte, []byte, error) {
 	return cmakeExec(cmake.ConfDir,
 		"--build", cmake.BuildDir,
-		// "--parallel "+strconv.FormatInt(int64(runtime.NumCPU()/2), 10),
+		"--parallel "+strconv.FormatInt(int64(runtime.NumCPU()/2), 10),
 	)
 }
 
@@ -204,7 +204,7 @@ func (cmake *Cmake) BuildDefaultsWithConfig(config string) ([]byte, []byte, erro
 	return cmakeExec(cmake.ConfDir,
 		"--build", cmake.BuildDir,
 		"--config", config,
-		// "--parallel "+strconv.FormatInt(int64(runtime.NumCPU()/2), 10),
+		"--parallel "+strconv.FormatInt(int64(runtime.NumCPU()/2), 10),
 	)
 }